Industrial polyamide yarn, preparation method therefor, and use thereof

Abstract

Disclosed are an industrial polyamide yarn, a preparation method therefor, and the use thereof. The raw materials for producing the industrial polyamide yarn include at least 1,5-pentanediamine and a linear aliphatic dibasic acid; or polyamide 5X obtained by the polymerization of 1,5-pentanediamine and a linear aliphatic dibasic acid as monomers. The industrial polyamide yarn according to an embodiment has the characteristics of a low water absorption, a good dimensional stability, a high fracture strength, and a good heat resistance.

1 . A polyamide industrial yarn, the raw materials for producing the industrial polyamide yarn at least comprise: 1,5-pentanediamine and a linear aliphatic dibasic acid; or polyamide 5X obtained from polymerization of 1,5-pentanediamine and a linear aliphatic dibasic acid as monomers. 
     
     
         2 . The polyamide industrial yarn according to  claim 1 , wherein the linear aliphatic dibasic acid contains 6 to 18 carbon atoms. 
     
     
         3 . The polyamide industrial yarn according to  claim 1 , wherein the linear aliphatic dibasic acid is selected from one or more of adipic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic add, hexadecane dibasic acid, heptadecanedioic acid, octadecanedioic acid, maleic acid and Δ9-1,18 octadecenedioic acid. 
     
     
         4 . The polyamide industrial yarn according to  claim 1 , wherein the polyimide industrial yarn has a moisture regain of ≤2.2%. 
     
     
         5 . The polyamide industrial yarn according to  claim 1 , wherein the polyamide industrial yarn has a breaking tenacity of 7.5 to 9.5 cN/dtex; and a retention rate of the heat-resistant strength of 85 to 95% after humidity conditioning, the retention rate of the breaking tenacity of the polyamide industrial yarn is ≥92%. 
     
     
         6 . The polyamide industrial yarn according to  claim 1 , wherein the polyamide industrial yarn has an elongation at break of 16 to 24%. 
     
     
         7 . The polyamide industrial yarn according to  claim 1 , wherein the polyamide industrial yarn has a modulus of ≥35 cN/dtex. 
     
     
         8 . The polyamide industrial yarn according to  claim 1 , wherein the polyamide industrial yarn has a heat shrinkage of ≤10.0%. 
     
     
         9 . The polyamide industrial yarn according to  claim 1 , wherein the polyamide industrial yarn has a boiled water shrinkage of ≤9.0%, and an elongation after boiled in water of ≤25.0%. 
     
     
         10 . The polyamide industrial yarn according to  claim 1 , obtained from spinning raw materials by a spinning process, and the spinning raw materials comprise a polyamide 5X resin, and the relative viscosity of the polyamides 5X resin in 96% sulfuric acid is 2.2-2.7. 
     
     
         11 . The polyamide industrial yarn according to  claim 10 , wherein the polyamide 5X resin comprises a thermal stabilizer and/or a second additive, the thermal stabilizer comprises one or more of copper acetate, potassium iodide, copper chloride, cuprous iodide, cupric oxide, and cuprous oxide; the second additive comprises one or more of a matting agent, a flame retardant, an antioxidant, an ultraviolet absorber, an infrared absorber, a crystal nucleating agent, a fluorescent brightener and an antistatic agent. 
     
     
         12 . A method for preparing the polyamide industrial yarn according to  claim 1 , comprising the steps of:
 (1) heating spinning raw materials to a molten state to form a melt, the spinning raw materials comprise a polyamide 5X resin;   (2) drawing the melt to form un-drawn yarn; and   (3) subjecting the un-drawn yarn to heat preservation, cooling, oiling, pre-tangling, multi-stage drawing, main tangling and winding to obtain the polyamide industrial yarn;   wherein a tension heat-setting treatment and/or a relaxation heat-setting treatment are performed in any one stage of the multi-stage drawing.   
     
     
         13 . The method according to  claim 12 , wherein the polyamide 5X resin has a relative viscosity in 96% sulfuric acid of 2.8 to 4.0, and the water content of the polyamide 5X resin is 100 to 1000 ppm. 
     
     
         14 . The method according to  claim 13 , wherein, the method for preparing the polyamide 5X resin comprises the steps of:
 subjecting the polyamide 5X resin having a relative viscosity of 2.2 to 2.7 in 96% sulfuric acid to high-temperature drying treatment to obtain a tackified polyamide 5X resin; and   subjecting the tackified polyamide 5X resin to resin humidity conditioning treatment to obtain the polyamide 5X resin having a relative viscosity of 2.8 to 4.0.   
     
     
         15 . The method according to  claim 14 , wherein the high-temperature drying treatment is performed under negative pressure state or inert gas protection, and the vacuum degree of the negative pressure state is −0.06 to −0.1 MPa;
 the temperature of the high-temperature drying treatment is 130 to 160° C., and the treatment time is 10 to 25 h. 
 
     
     
         16 . The method according to  claim 14 , wherein the temperature of the resin humidity conditioning treatment is 85 to 110° C.; the resin humidity conditioning treatment is performed by using nitrogen mixed with water steam, and the nitrogen dew point is controlled at −15 to 15° C. 
     
     
         17 . The method according to  claim 12 , wherein said heating in said step (1) is performed in a screw extruder, and the screw extruder is divided into five zones for heating, the temperature in the first zone is 220 to 250° C., the temperature in the second zone is 230 to 260° C., the temperature in the third zone is 240 to 270° C., the temperature in the fourth zone is 250 to 280° C., and the temperature in the fifth zone is 260 to 290° C. 
     
     
         18 . The method according to  claim 12 , wherein said step (2) comprises: ejecting the melt through a spinneret of a spinning head to obtain the un-drawn yarn; the temperature of the spinning head is 260 to 290° C., and the pressure of the spinning assembly of the spinning head is 10 to 22 MPa. 
     
     
         19 . The method according to  claim 12 , wherein said step (3) adopts an annealer for heat preservation, the annealing height is 100 to 300 mm, and the annealing temperature is 200 to 300° C.;
 the cooling treatment is air cooling by side blowing or ring blowing; 
 in the oiling treatment process, the height of the oiling lip from the spinneret is ≥2.5 m, and the oil pick-up is 0.7 to 1.2%; 
 the pre-tangling pressure is 1 to 2.5 bar; 
 the total draw ratio of the multi-stage drawing is 4.5 to 6.0; 
 the temperature of the tension heat-setting treatment is 150 to 200° C.; 
 the temperature of the relaxation heat-setting treatment is 100 to 160° C. 
 
     
     
         20 . A sewing thread, a tire cord, an airbag yarn, a mold-releasing cloth, a water cloth, a canvas, a safety belt, a rope, a fishing net, an industrial filtering cloth, a conveyor belt, a parachute, tent or a luggage comprising the polyamide industrial yarn according to  claim 1 .